The present invention relates generally to the field of telecommunications, and more specifically, to the field of integrating a portable telephone with other elements in a vehicle.
Many portable telephones, referred to simply as "portables," have input/output (I/O) interfaces which allow them to be coupled to, and to communicate with, accessory products such as car kits (including portable telephone holders, speakers, microphones, external antennas, etc.), chargers, cigarette lighter adapters, external keypads/control units, etc. The I/O interface is normally a serial databus interconnection which accommodates data communications. For example, some portables receive keystrokes and other limited information for portable operations from accessories on an ACCESSORY-to-PORTABLE data line (also called a "forward" data line) and, likewise, transmit display commands and status information to accessories on a PORTABLE-to-ACCESSORY data line (also called a "reverse" data line). This implementation is limiting from the perspective that it does not provide a way for other devices to tap into various other resources and capabilities of the portable.